Terrestrial Availability of UVA Radiance for Photoactivity Excitation Using Solar Radiation

An estimation of the terrestrial availability of ultraviolet (UV) radiation of the solar radiation is important in designing solar panels, many cosmetic and health products, agriculture and environment that utilized UV-active materials. A linear scale for dosage recommended by the World Health Organization (WHO) indicates the risk of potential sunburn. This linear scale, known as the UV index (UVI), is determined from the amount of radiation in the spectral range that includes both sunburn causing and carcinogeneous UVB, and sun–tanning UVA. UVI requires to be rationalized for estimating terrestrial availability of UVA for practical applications of UVA active materials such as photocatalysts that can be activated for photovoltaic and photosterlisation conversion of natural light. Based on harmonization of literature data and our own investigation, we elaborate a general guideline of the terrestrial availability of UVA radiation to estimate the minimum and maximum value of UVA radiance that can be used to benchmark the performance of materials active in this region. This general guideline will be highly useful in photocatalyst design and validation under simulated solar UV conditions leading to performance prediction of products when working in natural light.